Over the years I've worked out, I have noticed many different styles of weight-lifting exercises. One has me perplexed. Some people move the weights at a slow speed; others move them very quickly. Aerobics aside, why is it both types of people still look fit yet they exercise so differently? By the way, most people in my gym exercise with the weights pretty quickly.

-- Speed-Freak

Dear Speed-Freak:

I have been working out for a very long time and have observed this seeming contradiction of techniques. As you have stated, some people train very slowly. Others are moving so fast I sometimes wonder if they are getting any benefit from the training. It wasn't until I went to school to learn exercise physiology that it became all too apparent what's going on.

Allow me give you a brief lesson in skeletal muscle structure -- after all, you lift weights with your muscles.

The red fast twitch fibers can better sustain a load over long periods of time, like when you go hiking and carry a backpack. Another example would be if you box.

The red slow twitch fibers produce energy and can be used over much longer time periods, such as running a marathon or participating on a rowing team. A person with a predominance of these types of fibers would be well suited to these kinds of endurance activities.

All three of these muscle fibers occur randomly with each other in bundles called motor units. We can now biopsy muscles on humans and determine which motor units predominate in a particular human. The former Soviet Union was exceptionally well-versed in this technique. This told them early on in a child's life what type of athletic event they would be good at. The Soviet's won many gold medals in weightlifting, by the way.

Simply stated, it would be wise for individuals who lift weights to try and stimulate all three types of these muscle fibers. So perhaps you may be observing people who are predominately fast or slow and are accomplished in producing the desired result within their workouts by moving at varying speeds. It may feel correct to some to lift very slowly because of this predominance of fibers. Others, quickly.

The other possibility is that it is far easier to fling the weights around very fast!

Go figure.

-- Mr. Fitness

Tony Wagner, aka Mr. Fitness, has over 30 years of fitness and nutritional expertise. A certified personal trainer and fitness author, he has helped thousands of people get into and stay in shape. Contact him at: mrfitness1@aol.com, Facebook us,and stop by Bodyzone Fitness Center, 2740 N. Roosevelt Blvd., 305-292-2930.